1. Field of the Invention
This invention pertains to the feeding and stacking of items such as stuffed envelopes, and particularly to methods and apparatus for feeding and stacking such items on-edge.
2. Prior Art and Other Considerations
The prior art includes teachings of envelope processing systems wherein envelopes in a stack are conveyed on-edge in a feed direction toward a feeder for redirecting the envelope toward a singulation gap. The feeder, such as a revolving endless belt, for example, contacts a sidewall of a lead envelope for directing the lead envelope, in a direction orthogonal to the feed direction, toward the singulation gap.
Prior art envelope processing systems of the type just described have considerable difficulty in handling envelopes of varying thicknesses. Accordingly, significant problems are encountered when the same envelope processing system is expected to run a batch of envelopes which includes both thick and thin stuffed envelopes. If the singulation gap is sized for large envelopes, then a plurality of envelopes ("doubles") might be fed essentially simultaneously through the singulation gap. On the other hand, if the singulation gap is sized for small envelopes, the envelope processing system may fail to direct a thicker envelope toward and through the singulation gap.
Envelope processing systems which handle on-edge envelopes also are very awkward in stacking envelopes after the envelopes have undergone a processing (such as character reading or label printing). The potential interference with envelopes already-stored in a discharge stack poses problems for the introduction of an another on-edge envelope into the stack. Such unwelcomed interference is typically occasioned by a potentially obstructive path of envelope travel; by a high degree of friction between envelopes and the stack-defining structure wherein they travel; and, by difficulty in obtaining and maintaining proper registration of the envelopes introduced into the discharge stack.
In view of the foregoing, an object of the present invention is the provision of method and apparatus for facilitating the handling of envelopes of varying thicknesses by an on-edge envelope processing system.
An advantage of the present invention is the provision of method and apparatus for facilitating the feeding of envelopes of varying thicknesses in an on-edge envelope processing system.
Another advantage of the present invention is the provision of method and apparatus for facilitating the introduction of processed envelopes into a discharge stack wherein the envelopes are oriented on-edge.
A further advantage of the present invention is the provision of method and apparatus for facilitating the smooth and silent stacking of on-edge envelopes in a discharge stack wherein envelopes are oriented on-edge.